<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<!--alert方法是弹出框
onclick 点击事件属性-->
<input type="button" value="按钮" onclick="alert('内联引入成功!')">

<script>
    alert("内部引入成功！")
</script>
<!--引入外部js文件-->
<script src="my.js"></script>
</body>
</html>